SINGAPORE - Conservatives are on the decline. Compared to five years ago, the proportion of Singaporeans labelled as politically conservative shrank by more than half: from 44.3 per cent to 18.5 per cent.

This category of voters is described in the Institute of Policy Studies (IPS) post-GE2020 survey as those who disagree with the need for change in the electoral system, checks and balances, and different voices in Parliament.

On the other hand, the proportion in the swing category - defined as being mixed in their views compared to the pluralists and conservatives - shot up by more than 20 points to 59.2 per cent.

Pluralists, or those who desire more political diversity, rose slightly by 4.4 percentage points to 22.4 per cent.

Dr Teo Kay Key said the surge in the swing category is "surprising", given that most would expect stronger growth in the proportion of pluralists amid calls for more opposition presence in Parliament.

"Perhaps people want some kind of representation and some checks and balances, but not all the way to the pluralist end," said Dr Teo, a post-doctoral fellow at the IPS Social Lab and a member of the survey team.

"(Pluralist) demands may have been tempered by other governance issues such as the need for efficient government, which is one of the top three issues shaping voting decisions among all three categories."

The IPS research team stressed that the survey results reflect the respondents' concerns and political preferences, but do not tell exactly which party they voted for in GE2020.

In the past three general elections, pluralists have always been younger - especially those aged 21 to 29 - university-educated, and more well-off.

But what stood out this year was the increase in their proportion among the lowest-income households earning less than $2,000 a month, and those with non-tertiary post-secondary qualifications.

IPS said this points to two effects taking place.

First, the consistent trend of those in the higher socio-economic class supporting political pluralism.

Second, the effects of bread-and-butter issues at the other end of the socio-economic spectrum, such that respondents felt there was a need for political opposition in Parliament.

"It is quite consistent that those in the higher socio-economic classes will think very clearly about the role of political competition and pluralism," said Dr Gillian Koh, a senior research fellow at IPS who led the research team behind the survey.

She noted that the biggest shift this year was not to the pluralist group, but to the swing category.

How respondents eventually voted, she added, would then depend on other factors such as the attributes of the individual electoral candidates.